Description from Flora of China
Sarcopodium rotundatum Lindley, Fol. Orchid. 2(Sarcopodium): 2. 1853; Bulbophyllum rotundatum (Lindley) H. G. Reichenbach; Callista rotundata (Lindley) Kuntze; Dendrobium rotundatum (Lindley) J. D. Hooker; Katherinea rotundata (Lindley) A. D. Hawkes.
Rhizome many branched, covered with papery tubular sheaths ca. 1 cm. Pseudobulbs borne 3-11 cm apart on rhizome, often ± curved, ascending, narrowly ovoid, 20-30 × 4-7 mm, 2-leaved, with scalelike basal sheaths. Leaf blade oblong or elliptic, 6-9 × 1.5-2.5 cm, leathery, apex retuse; petiole 5-10 mm. Inflorescence 1-flowered; peduncle ca. 5 mm, enclosed in large membranous sheaths; floral bracts ovate, small, ca. 1 cm, membranous. Flowers yellowish brown; pedicel and ovary ca. 2 cm. Dorsal sepal ovate-lanceolate, 22-32 × ca. 7 mm, acute; lateral sepals lanceolate, 22-35 × 8-10 mm. Petals oblong-lanceolate, ca. 23 × 5-6 mm, acuminate; lip obovate-oblong in outline, ca. 20 mm, 3-lobed; lateral lobes subovate; mid-lobe ca. 11 mm wide, adaxially with a triangular thickened keel, margin thin, undulate, subreniform to obscurely bilobed, emarginate; disk with 3 lamellae, median much shorter. Column ca. 1 cm, foot ca. 1 cm. Fl. Mar-May.
Lithophytic on rocks or epiphytic on tree trunks in open forests or at forest margins; 1300-2500 m. Guangxi, SE Xizang, NW and SE Yunnan [Bhutan, NE India, Myanmar, Nepal].